Economical driving by efficient utilisation of the kinetic energy of vehicles such as trucks with a view to fuel saving is becoming increasingly common. One way of achieving it is to minimise the use of brakes on downhill runs, preferably by the driver releasing the accelerator in good time before the declivity and thereby throttling the fuel supply, resulting in a reduction in the vehicle's speed. This loss of speed is then recouped “gratis” downhill.
A known practice is to use the vehicle's cruise control to run the vehicle in a fuel-economizing way on the basis of the vehicle's location and map data along its itinerary by varying its speed on the basis of the nature of the topology ahead.
It is however not always appropriate to use the cruise control, e.g. on winding and hilly roads where the need to utilise the vehicle's kinetic energy for fuel saving may be greater and the demands upon the driver correspondingly more exacting. Some drivers will also choose not to use the cruise control. Fuel economy is thus made difficult in situations where cruise control guidance based on map data along the itinerary is not employed.